Sudhir Agrawal

Modified HLR-VLR Location management scheme in PCS network

This paper proposes a modified version of conventional HLR/VLR scheme for improving the location management in PCS network. The conventional HLR/VLR scheme suggests that when a mobile terminal (MT) moves from one LA to another LA which is served by different VLR, it registers itself with new VLR along with HLR, at the same time HLR deregisters the mobile terminal from the old VLR and acknowledges the receipt of the message to new VLR. The modified version proposes that there is no requirement of deregistering of mobile terminal from old VLR at the same time when MT registers at new VLR and so message transmission cost and database overload can be reduced. Numerical analysis is done for both conventional and modified version and compared together. The numerical results are promising and a significant total cost reduction is obtained with proposed scheme.

Location Management Optimization Schemes for Cellular System

The ever-increasing demand of mobile system is posing a great challenge for efficient call delivery due to tremendous surge in numbers of mobile subscribers. In order to scale well with increased users, the efforts are underway to develop the new location management techniques as well as to optimize the existing ones so as to keep up-to-date information about current location of mobile phones without causing much traffic load in cellular network. Various location management optimization approaches are being explored and developed by research community in recent past. This papers sheds light on various such approaches in order to give a comprehensive overview of research registered in this field..

Eco-Friendly Green Liquid Chromatographic Separations of a Novel Combination of Azelastine and Fluticasone in the Presence of Their Pharmaceutical Dosage form Additives

Background: The first highly sensitive, rapid and specific green microemulsion liquid chromatographic (MELC) method was established for the simultaneous estimation of fluticasone propionate (FLU) and azelastine HCl (AZL) in the presence of their pharmaceutical dosage form additives (phenylethyl alcohol (PEA) and benzalkonium chloride (BNZ)). Methods: The separation was performed on a C18 column using (o/w) microemulsion as a mobile phase which contains 0.2 M sodium dodecyl sulphate (SDS) as surfactant, 10% butanol as cosurfactant, 1% n-octanol as internal phase and 0.3% triethylamine (TEA) adjusted at pH 6 by 0.02 M phosphoric acid; with UV detection at 220 nm and programmed with flow rate of 1 mL/min. Results: The validation characteristics e.g. linearity, lower limit of quantification (LOQ), lower limit of detection (LOD), accuracy, precision, robustness and specificity were investigated. The proposed method showed linearity over the concentration range of (0.5-25 μg/mL) and (0.1-25 μg/mL) for FLU and AZL, respectively. Besides that, the method was adopted in a short chromatographic run with satisfactory resolution factors of (2.39, 3.78 and 6.74 between PEA/FLU, FLU/AZL and AZL/BNZ), respectively. The performed method was efficiently applied to pharmaceutical nasal spray with (mean recoveries ± SD) (99.80 ± 0.97) and (100.26 ± 0.96) for FLU and AZL, respectively. Conclusion: The suggested method was based on simultaneous determination of FLU and AZL in the presence of PEA and BNZ in pure form, laboratory synthetic mixture and its combined pharmaceutical dosage form using green MELC technique with UV detection. The proposed method appeared to be superior to the reported ones of being more sensitive and specific, as well as the separation was achieved with good performance in a relatively short analysis time (less than 7.5 min). Highly acceptable values of LOD and% RSD make this method superior to be used in quality control laboratories with of HPLC technique. A R T I C L E H I S T O R Y Received: January 27, 2018 Revised: June 22, 2018 Accepted: June 27, 2018 DOI: 10.2174/1573411014666180727130722

Software Defined Millimeter Wave 5th Generation Communications System

A row column Diagonal (RCD) based data security method has been disused here for software defined millimeter wave (SDMW) based 5th generation (5G) millimeter wave (MW) communication system. The RCD based security method in this research paper discusses encryption and decryption technique for 5G SDMW based cloud computing environment (CCE) and fog computing environment (FCE). The Fog computing is an emerging technology trend and complementing along with Cloud computing. Fog Computing along with Cloud computing considers various emerging applications of ubiquitous computing, Internet of Flying-Things (IoT) and 5G millimeter wave (MW) communication system. FCE also provides data storage for user and groups at personal and professional level along with the application services. In this paper we are discussing, data security need and demand for Fog computing and Cloud computing. RCD based encryption and decryption module is very secure and useful. This proposed security method is easy to develop and integrate in SDMW based 5G millimeter wave (MWe) communications system. This research is promising high quality security for the 5G MW communications system to provide efficient and optimum security.

Performance Analysis of De-registration Strategies in Personal Communication Network

a mobile terminal (M T) leaves its registration area (RA) and enters into new RA, the serving Visitor Location Register (VLR) sends a registration request to the Home Location Register (HLR).On receiving this request the HLR sends a de-registration request to the old VLR (which was serving the M T).After deregistering the M T, the old VLR acknowledges the request of HLR and then the HLR confirms the registration of the MT by sending the acknowledgement message to the new VLR. This approach is called explicit de- registration scheme. Implicit de-registration is a variant scheme, in which we can save the cost by ignoring the explicit de-registration message to the old VLR and its acknowledgement to the HLR. In terms of cost, implicit de- registration strategy is efficient than the explicit as we are saving de-registration signal exchange cost. However, at old VLR we may have the invalid entries. These invalid entries increase the database size at the VLR. To remove the invalid entries from the VLR, various de-registration schemes were suggested like polling, timeout and the group de-registration scheme. In this paper a comparative analysis is performed. On the basis of the cost incurred and the numerical result shows that the group de-registration scheme is efficient than the timeout and polling scheme.

Performance Evaluation of Location Management Techniques in PCS Network

Location management being a major part of cellular network provides mobility to mobile subscribers. The current location information is required to route the call correctly to the recipient irrespective of its current location. The current HLR/VLR architecture for location management in standards like IS-41 & GSM suffers from call setup delay due to network congestion and also prone to failure due to its centralized nature. This paper attempts to make an evaluation of the optimized location management techniques suggesting fully distributed, hierarchical and multi HLR approach against the conventional one and also highlights the pros and cons of all the reviewed techniques.